Lecture 7 RH

Question 1

What is the function of the fibrous skeleton of the heart?

Answer 1

The fibrous skeleton of the heart is important for anchoring the valves.

The fibrous skeleton provides structural support for the heart

Question 2

What is the function of the vagus nerve?

Answer 2

vagus nerve decreases heart rate and force of contraction. It runs anteriorly to the root of the lung.

Question 3

Where do the sympathetic preganglionic neurons that innervate the heart originate from?

Answer 3

Preganglionic neurons originate from T1-T4 lateral horns and synapse at the sympathetic trunk.

Question 4

What nerves does the cardiac plexus contain?

Answer 4

Contains sympathetic and parasympathetic neurons bundled up in a hard to distinguish manner.

Question 5

Where do the visceral afferent neurones that arise from the heart enter the spinal cord?

Answer 5

visceral afferent neurones (bald eagle screech) end up in T1 -T4

Question 6

What are the components of the pericardium?

Answer 6

pericardium is a double layered membrane with a visceral layer around the heart and a parietal layer of serous pericardium.

Pericardium anchors the heart to the diaphragm’s central tendon.

Question 7

How does the heart beat without being inhibited by the structures around it?

Answer 7

Fluid around the heart within the serous membrane allows less friction to exist.

Question 8

What is the endocardium?

Answer 8

Endo cardium is the inside layer of the heart which is in contact with the blood the heart is pumping

Question 9

What is the epicardium?

Answer 9

Epicardium is equiavalent to the visceral pleura

Question 10

What is the myocardium?

Answer 10

The intermediate layer between the epi and endo cardium. This layer consists mostly of the muscle.

Question 11

What is a probable problem of the pericardial space?

Answer 11

effusion can occur into it which would limit ventricle contraction.

Question 12

What nerves innervate the pericardium?

Answer 12

Right and left phrenic nerves give branches to the pericardium and the afferent fibers go to C3,4,5.

Question 13

What are pericardial sinuses?

Answer 13

pericardial sinuses are spaces inside pericardial cavity.

Question 14

What is the outermost layer of the pericardium?

Answer 14

The fibrous pericardium.

Question 15

What are the types of sinuses present in the pericardium?

Answer 15

Transverse sinuses

Oblique sinuses

Question 16

What is the clinical significance of the oblique sinus of the pericardium?

Answer 16

Deepest and most inferior part when patient is on their back which means this is the location where fluid effusion can occur. As a result of this the left ventricle and atrium can suffer.

Question 17

Where does the oblique sinus of the pericardium run?

Answer 17

pericardial cavity behind the heart near the apex the pericardium runs obliquely and forms the oblique sinus.

Question 18

Where does the transverse sinus of the pericardium run?

Answer 18

behind the roots of the aorta and pulmonary trunk anteriorly and the pulmonary veins inferiorly.

Question 19

What is the clinical significance of the transverse sinus?

Answer 19

Roots in and around and behind and around the aorta and pulmonary trunk can be accessed through this sinus.

Question 20

What landmarks are coronary arteries commonly associated with?

Answer 20

The grooves of the heart

Question 21

Where do the coronary arteries originate from?

Answer 21

2 main arteries; taking origin from ascending aorta (first branch) directly superior to the semilunar aortic valves.

Question 22

Where does the left coronary artery run and what branches does it give off?

Answer 22

Left coronary artery runs behind the pulmonary trunk and gets access to left atrioventricular groove and all the way around posterior aspect of the heart. It forms 2 branches; anterior interventricular branch and the circumflex branch. Left coronary artery wraps around left side of the heart and gives off a marginal branch to provide blood to the left ventricle.

Question 23

What is another name for the anterior interventricular branch?

Answer 23

anterior interventricular branch is also known as the left descending artery.

Question 24

Where does the right coronary artery run and what branches does it give off?

Answer 24

Right coronary artery runs through right atrioventricular groove and gives off right marginal artery as it wraps around the back of the heart and continues posteriorly to the midline of the heart. It usually gives off the posterior interventricular branch. It also gives a branch to the sinoatrial node and the atrioventricular node.

Question 25

Which artery supples the posterior interventricular groove?

Answer 25

right coronary artery gives off the posterior interventricular artery but only in the case of a right dominant circulation. In the left dominant circulation the circumflex artery supplies the posterior interventricular groove.

Question 26

What parts of the heart does the right coronary artery supply?

Answer 26

right atrium

Most of right ventricle

diaphragmatic surface of left ventricle

sometimes gives off a branch to the sinoatrial node (55% of times)

Atrioventricular node (90% of times(

Question 27

What parts of the heart does the left coronary artery supply?

Answer 27

Most of left atrium and ventricle

Some of right ventricle via branches from anterior interventricular artery.

In some cases a branch to the SA node (45%)

In rare cases to AV node (10%)

Question 28

What are the anastomoses that exist between coronary arteries?

Answer 28

posterior to the apex between the posterior interventricular branch anastomoses with anterior interventricular branch of the left coronary artery

Question 29

What kind of end arteries are coronary arteries?

Answer 29

Coronary arteries are functional end arteries. They don’t actually connect unless a slow occlusion occurs because it stimulates production of more arteries. Sudden occlusions cause myocardial infarctions.

Question 30

What happens during coronary heart disease?

Answer 30

blockages in coronary arteries prevent oxygen from reaching the heart and as a result tissues die and stimulate visceral afferent neurons which cause pain to be felt.

Question 31

How is angiography carried out?

Answer 31

A catheter is inserted into aorta and added into the coronary arteries and radio opaque dye is injected into them and this is visible on a screen.

Question 32

What is angioplasty?

Answer 32

angioplasty involves adding a balloon into the narrowing of the coronary artery and then inflating the balloon and this removes the blockage.

Question 33

What is coronary bypass?

Answer 33

Coronary bypass involves getting a blood vessel from elsewhere and using it to replace the coronary arteries with it. typical arteries to be used for this are the radial artery and the small saphenous vein.

Triple bypass can involve multiple arteries that are used to replace coronary arteries.

Question 34

What is the purpose of the coronary sinus?

Answer 34

Coronary sinus sits on the posterior aspect of the heart between left atrium and left ventricle and is a big swollen vein which has an opening in the right atrium.

Question 35

Where is the great cardiac vein located?

Answer 35

wrrapping around the left side of the heart and going through anterior interventricular groove is the great cardiac vein.

Question 36

What vein drains the right side of the heart?

Answer 36

right side of the heart is drained by small cardiac vein

Question 37

what vein drains the left side of the heart?

Answer 37

left side of the heart mainly drained by left marginal vein.

Question 38

How does the impulse from the SA node not affect the ventricles?

Answer 38

Muscles of atrium and ventricles are separated by the fibrous skeleton.

Question 39

What is the benefit of having the AV node?

Answer 39

AV node allows the ventricles to contract after considerable time from the SA node.

Question 40

Papillary muscles are distant, how do heart muscles allow them to contract in a timely manner?

Answer 40

left and right ventricular branches run to each individual ventricle. Papillary muscles are distant. This is fixed by the moderator band.

Question 41

What happens to the AV node when the SA node stops working efficiently?

Answer 41

AV node can control the entire heart when SA node is damaged

Question 42

How is a damaged pacemaker repaired surgically?

Answer 42

Installation of new artificial pulse generator above pec major.